1. Field of the Invention
This invention relates to reaction products of allantoin and formaldehyde and, more particularly, to such products which contain very low levels of free formaldehyde (<0.1%), while retaining advantageous, long-lasting anti-microbial properties, particularly against the organism B. cepacia. 
2. Description of the Prior Art
Berke, P. A., in U.S. Pat. No. 3,248,285 described a reaction product of allantoin and formaldehyde (Germall® 115) from the reactants in a mole ratio of 1:1.5, respectively; and in U.S. Pat. No. 4,271,176 and Reissue 32,848, (Germall® II) in a mole ratio of 1:4. However, during recent evaluations using modern C13 NMR techniques, these reaction products were found to contain 0.5% to 1.0% of free formaldehyde. This amount was considered in the past to be necessary to retain its anti-microbial activity; although now it is recognized that a considerable amount of free formaldehyde in the product is disadvantageous from a safety (irritation) and environmental standpoints.
Accordingly, it is an object of this invention to prepare reaction products of allantoin and formaldehyde which have long-lasting anti-microbial properties with the presence therein of only very low levels of free formaldehyde (i.e. <0.1%).
Another object of the invention is to provide a method of making such effective reaction products.
Still another object of this invention is to provide a synergistic combination of such products with other known fungicides to obtain broad spectrum activity against bacteria and fungi, yeast, molds, and the like.